Improvement in lifting-jacks



UNITED STATES PATENT OFFICE.

JACOB o. JoYoE, OF- DAYTON, OHIO.

IMPROVEMENT IN LIFTlNG-JACKS.

Specification forming part of Letters Patent No. 172,924, dated February1, 1876; application filed July 30, 1875.

To all whom it may concern:

Be it known that I, JACOB O. JOYCE, of Dayton, in the county ofMontgomery and State of Ohio, have invented certain Improvements inLifting-Jacks,of which the following is a specification: I

This invention relates to certain improvements in the construction ofliftingjacks, which are fully described hereinafter.

- Inthe accompanying drawing, Figure 1 represents a central verticalsection of my improved lifting-jack, and Fig. 2 a transverse section onthe line .70 w'of Fig. 1. The letters A A represent the sides of theframe, and a a the front and rear portions thereof, and B the base, allof which'are preferably cast in a single piece, with a vertical slotextending from near the top to the bottom, in the rear part a of theframe, as indicated, between the letters a a. The front part a of theframe terminates at a suificient distance below the. top of this slot topermit of the ready introduction of the lifting-bar G. In suitableprojecting and curved portions of the side frames A A, at the front ofthe jack, is journaled the lifting-lever E, and within a rounded seat inthe end of this lever is arranged the liftiug-pawl G, the lower end ofwhich is also rounded, as at 9, so as to 'form what might be termed aknuckle-joint. The

head of the lever is provided with a rounded surface, 0, so that whenthe lever is suflicient 1y elevated, the said surface will come incontact with the liftingpawl G, and throw or force the same inengagement with the rackbar 0.

The lifting-pawl G, by this construction and arrangement, will inclineat an angle to aperpendicular line drawn through the center of 9, sothat its own weight will cause it to engage quickly with the teeth ofthe ratchet c on the lifting-bar O.- Y

The head of the lifting-pawl is provided with a thumb-piece orprojection, g, by which it may be caught and drawn back when thelifting-bar is to be run down in the frame. The holding-pawl I ispivoted, as at c, between theside frames A A, and its head takes againstor under the notches in the lifting-bar C, to hold said bar while thelifting-lever is raised to take a new purchase or set. The

holding-pawl I is thrown inward against the notches of the bar 0 by aspring, 8, as shown, and is provided with a thumb-piece, V, by which itmay be drawn back when desired.

The cylindrical pawl-seatin the lever E is, made in the form of an arcof a circle, but

It represents an elastic substance, rubber being preferred, situated inthe base B of-the jack, which is intended to deaden the blow caused bydropping the bar 0.

This enables me to dispense with the use of pins, &c., for the barto-fall and rest upon,

and obviates the danger of breakage occasioned by the bar droppingagainst the base.

I claim as my invention-'- 1. The lifting-lever E, with the circularseat formed of an are greater than half of a circle, with thecylindrical bearing of pawl G working therein, combined in the frame ofa liftingjack, in such a manner that the pawl can only be removedendwise, and when the lever is out of the frame, substantially as hereinset forth.

2. The combination, in a lifting-jack, of the lever E, having therounded surface 0, the

pawls G I, rack-bar 0, case A, and elastic cushion R, all constructedand arranged-as herein shown and described, for the purpose specified.

JACOB O. JOYCE. Witnesses:

0.. M. GoTTscHALL, E. RSTILWILL.

